package mainimport (	"fmt"	"strconv"	"strings"	"time")func main() {	for i := 0; i <= 50; i++ {		time.Sleep(100 * time.Millisecond)		h := ""		if 0 == i || i == 50 {			h = strings.Repeat("=", i) + strings.Repeat(" ", 50-i)		} else {			h = strings.Repeat("=", i-1) + strings.Repeat(">", 1) + strings.Repeat(" ", 50-i)		}		fmt.Print("\r" + "[" + h + "]" + strconv.Itoa(i*2) + "%")	}	fmt.Println("OK!")}